Updated on 2024/08/22

Information

 

写真a

 
FUKUI TOKURO
 
Organization
Faculty of Arts and Science Division for Theoretical Natural Science Assistant Professor
Title
Assistant Professor
Contact information
メールアドレス
Profile
[研究活動] 「核力は核子多体系をどのように支配しているのだろうか?」先人たちが長年挑んできたものの未だ完全な答えが得られていないこの問いに対して、先鋭的理論を駆使して挑戦している。最近は重いクォークを含むハドロン間相互作用や、宇宙元素合成で鍵となる核反応の精密計算、中性子星の物理などにも興味を持っている。 [教育活動] 基幹教育のうち、「自然科学総合実験」や「基礎科学実習」、「基幹教育セミナー」を担当している。また総合科目「実践!はじめての研究」を担当し、学生の "研究" への挑戦を後押ししている。

Research Areas

  • Natural Science / Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics

Degree

  • Doctor of Philosophy (Science)

Research History

  • Kyushu University Faculty of Arts and Science Assistant Professor 

    2022.11 - Present

      More details

    Country:Japan

    researchmap

  • RIKEN RIKEN Nishina Center for Accelerator-Based Science Visiting Researcher 

    2023.4 - Present

      More details

  • RIKEN RIKEN Nishina Center for Accelerator-Based Science Special Postdoctoral Researcher 

    2021.3 - 2022.10

      More details

    Country:Japan

    researchmap

Research Interests・Research Keywords

  • Research theme: Strong Interaction

    Keyword: Strong Interaction

    Research period: 2024

  • Research theme: Nuclear Astrophysics

    Keyword: Nuclear Astrophysics

    Research period: 2024

  • Research theme: Theoretical Nuclear Physics

    Keyword: Theoretical Nuclear Physics

    Research period: 2024

  • Research theme: Nuclear Force/Nuclear Structure/Nuclear Reaction

    Keyword: Nuclear Force/Nuclear Structure/Nuclear Reaction

    Research period: 2024

  • Research theme: Study of many-nucleon systems based on state-of-the-art theory

    Keyword: Theoretical Nuclear Physics, Nuclear Force, Nuclear Structure, Nuclear Reaction, Strong Interaction, Three-nucleon force, Nuclear Astrophysics

    Research period: 2010.4

Awards

  • Young Scientist Award of the Physical Society of Japan

    2022.3   Physical Society of Japan   Development of first-principles shell-model calculations via proper treatment of three-body force

    Tokuro Fukui

     More details

  • 2022年度基礎科学特別研究員成果発表会 優秀賞

    2023.1   理化学研究所   Presentation Award of FY2022 SPDR Presentation of Research Results, RIKEN

     More details

    理化学研究所基礎科学特別研究員の成果発表会において物理学Iの分野で優秀な研究成果および発表をした者に贈られる賞を受賞した。

  • Presentation Award of FY2022 SPDR Presentation of Research Results

    2023.1   RIKEN  

    Tokuro Fukui

     More details

  • 第16回(2022年)日本物理学会若手奨励賞

    2022.3   日本物理学会   Young Scientist Award of the Physical Society of Japan, 2022

Papers

  • Uncovering the mechanism of chiral three-nucleon force in driving spin-orbit splitting

    Tokuro Fukui, Giovanni De Gregorio, Angela Gargano

    Physics Letters B   855   2024.8   ISSN:0370-2693 eISSN:1873-2445

     More details

    Publishing type:Research paper (scientific journal)   Publisher:Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics  

    The three-nucleon force (3NF) is crucial in shaping the shell structure of atomic nuclei, particularly impacting the enhancement of spin-orbit (SO) splitting, especially in nuclei with significant deviations from stability. Despite its importance, the specific mechanisms driving this enhancement remain unclear. In this study, we introduce a decomposition scheme based on the rank of irreducible tensors forming the 3NF, derived from chiral effective field theory at next-to-next-to-leading order, to elucidate their influence on SO splitting. Within the shell-model framework, our analysis reveals that the rank-1 component of the 3NF is the primary factor enlarging the energy gap between the 0p3/2 and 0p1/2 single-particle levels in p-shell nuclei, while the rank-2 component makes a subdominant contribution. Since the rank-1 component originates exclusively from the 2π-exchange 3NF, our finding will not depend on the choice of the low-energy constants of contact terms. We also remark on the antisymmetry of the rank-1 3NF, which can affect the quantum entanglement of spin states. This study lays the groundwork for further exploration into this field toward a microscopic understanding of the 3NF impact on the nuclear shell structure.

    DOI: 10.1016/j.physletb.2024.138839

    Web of Science

    Scopus

    researchmap

  • Investigation of spatial manifestation of α clusters in 16O via α-transfer reactions

    Tokuro Fukui, Yoshiko Kanada-En'yo, Kazuyuki Ogata, Tadahiro Suhara, Yasutaka Taniguchi

    Nuclear Physics A   983   38 - 52   2019.3

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Recently, we have determined surface distributions of α clusters in the ground state of Ne20 from α-transfer cross sections, without investigating the properties of its excited states. In this paper we extend our comprehension of α-cluster structures in excited states of nuclei through reaction studies. In particular we focus on O16, for which attention has been paid to advances of structure theory and assignment regarding 4+-resonance states. We study the surface manifestation of the α-cluster states in both the ground and excited states of O16 from the analysis of the α-transfer reaction C12(Li6,d)16O. The α-transfer reaction is described by the distorted-wave Born approximation. We test two microscopic wave functions as an input of reaction calculations. Then a phenomenological potential model is introduced to clarify the correspondence between cluster-wave functions and transfer-cross sections. Surface peaks of the α-wave function of O16(0+) are sensitively probed by transfer-cross sections at forward angles, while it remains unclear how we trace the surface behavior of O16(4+) from the cross sections. From inspection of the cross sections at forward angles, we are able to specify that the α-cluster structure in the 01+ and 02+ states prominently manifests itself at the radii ∼4 and ∼4.5 fm, respectively. It is remarkable that the 41+ state has the C12+α-cluster component with the surface peak at the radius ∼4 or outer, whereas the C12+α-cluster component in the 42+ state is found not to be dominant. The 42+ state is difficult to be interpreted by a simple potential model assuming the C12+α configuration only.

    DOI: 10.1016/j.nuclphysa.2018.12.024

  • Realistic shell-model calculations for p -shell nuclei including contributions of a chiral three-body force

    T. Fukui, L. De Angelis, Y. Z. Ma, L. Coraggio, A. Gargano, N. Itaco, F. R. Xu

    Physical Review C   98 ( 4 )   2018.10

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    In this paper we present an evolution of our derivation of the shell-model effective Hamiltonian, namely introducing effects of three-body contributions. More precisely, we consider a three-body potential at next-to-next-to-leading order in chiral perturbation theory, and the induced three-body forces that arise from many-body correlations among valence nucleons. The first one is included, in the derivation of the effective Hamiltonian for one- and two-valence nucleon-systems, at first order in the many-body perturbation theory. Namely, we include only the three-body interaction between one or two valence nucleons and those belonging to the core. For nuclei with more than two valence particles, both induced - turned on by the two-body potential - and genuine three-body forces come into play. Since it is difficult to perform shell-model calculations with three-body forces, these contributions are estimated for the ground-state energy only. To establish the reliability of our approximations, we focus attention on nuclei belonging to the p shell, aiming to benchmark our calculations against those performed with the ab initio no-core shell model. The obtained results are satisfactory, and pave the way to the application of our approach to nuclear systems with heavier masses.

    DOI: 10.1103/PhysRevC.98.044305

  • Calculation of Gamow-Teller and two-neutrino double- β decay properties for Te 130 and Xe 136 with a realistic nucleon-nucleon potential

    L. Coraggio, L. De Angelis, T. Fukui, A. Gargano, N. Itaco

    Physical Review C   95 ( 6 )   2017.6

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We report on the calculation of Gamow-Teller and double-β decay properties for nuclei around Sn132 within the framework of the realistic shell model. The effective shell-model Hamiltonian and Gamow-Teller transition operator are derived by way of many-body perturbation theory, without resorting to the empirical effective quenching factor for the Gamow-Teller operator. The results are then compared with the available experimental data, in order to establish the reliability of our approach. This is a mandatory step before we apply the same methodology, in forthcoming studies, to the calculation of the neutrinoless double-β decay nuclear matrix elements for nuclei that are currently considered among the best candidates for the detection of this process.

    DOI: 10.1103/PhysRevC.95.064324

  • The role of three-nucleon potentials within the shell model: Past and present

    L. Coraggio, G. De Gregorio, T. Fukui, A. Gargano, Y.Z. Ma, Z.H. Cheng, F.R. Xu

    Progress in Particle and Nuclear Physics   134   104079 - 104079   2023.9   ISSN:0146-6410 eISSN:1873-2224

     More details

    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    We survey the impact of nuclear three-body forces on structure properties of nuclei within the shell model. It has long been acknowledged, since the seminal works of Zuker and coworkers, that three-body forces play a fundamental role in making the monopole component of shell-model Hamiltonians, derived from realistic nucleon–nucleon potentials, able to reproduce the observed evolution of the shell structure. In the vast majority of calculations, however, their effects have been taken into account by shell-model practitioners by introducing ad hoc modifications of the monopole matrix elements. During last twenty years, a new theoretical approach, framed within the chiral perturbation theory, has progressed in developing nuclear potentials, where two- and many-body components are naturally and consistently built in. This new class of nuclear forces allows to carry out nuclear structure studies that are improving our ability to understand nuclear phenomena in a microscopic approach. We provide in this work an update on the status of the nuclear shell model based on realistic Hamiltonians that are derived from two- and three-nucleon chiral potentials, focusing on the role of the three-body component to provide the observed shell evolution and closure properties, as well as the location of driplines. To this end, we present the results of shell-model calculations and their comparison with recent experimental measurements, which enlighten the relevance of the inclusion of three-nucleon forces to master our knowledge of the physics of atomic nuclei.

    DOI: 10.1016/j.ppnp.2023.104079

    Web of Science

    Scopus

    researchmap

  • Implementation of chiral two-nucleon forces to nuclear many-body methods with Gaussian-wave packets

    Tokuro Fukui

    Progress of Theoretical and Experimental Physics   2023 ( 7 )   2023.7   ISSN:2050-3911 eISSN:2050-3911

     More details

    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Oxford University Press (OUP)  

    Abstract

    Many-body methods that use Gaussian-wave packets to describe nucleon spatial distribution have been widely employed for depicting various phenomena in nuclear systems, in particular clustering. So far, however, the chiral effective field theory, a state-of-the-art theory of nuclear force, has not been applied to such methods. In this paper, we give the formalism to calculate the two-body matrix elements of the chiral two-nucleon forces using the Gaussian-wave packets. We also visualize the matrix elements and investigate the contributions of the central and tensor forces. This work is a foothold towards an ab initio description of various cluster phenomena in view of nucleons, pions, and many-nucleon forces.

    DOI: 10.1093/ptep/ptad087

    Web of Science

    Scopus

    researchmap

    Other Link: https://academic.oup.com/ptep/article-pdf/2023/7/073D03/51004209/ptad087.pdf

  • Femtoscopic study on the ΛΛ-NΞ interaction

    Yuki Kamiya, Kenji Sasaki, Tokuro Fukui, Tetsuo Hyodo, Kenji Morita, Kazuyuki Ogata, Akira Ohnishi, Tetsuo Hatsuda

    Suplemento de la Revista Mexicana de Física   3 ( 3 )   2022.9   eISSN:2683-2585

     More details

    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:Sociedad Mexicana de Fisica A C  

    The correlation functions of pΞ − and ΛΛ pairs from high-energy pp collisions are investigated in the coupled-channel formalism. The NΞΛΛ coupled-channel potentials obtained in the lattice QCD calculation at almost physical quark masses are employed. The pΞ − correlation function shows the large enhancement from the pure Coulomb case, while the ΛΛ correlation function shows the moderate enhancement from the pure quantum statistics case. This agreement indicates that both the NΞ and ΛΛ interactions are moderately attractive without having quasibound or bound state.

    DOI: 10.31349/suplrevmexfis.3.0308124

    researchmap

  • Femtoscopic study of coupled-channel baryon-baryon interactions with S = −2

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, T. Hatsuda

    Proceedings of Science   380   2022.5   eISSN:1824-8039

     More details

    Publishing type:Research paper (international conference proceedings)  

    The correlation functions of pΞ− and ΛΛ pairs from pp and pA collisions are studied in the coupled-channel framework using the NΞ-ΛΛ coupled-channel baryon-baryon potentials obtained in the lattice QCD calculation at almost physical quark masses. The pΞ− correlation function is calculated to be significantly enhanced from the pure Coulomb case, while the ΛΛ correlation function is slightly enhanced from that of the pure fermion quantum statistics. These features reflect the large and small scattering lengths in the pΞ− and ΛΛ channels in magnitude, and agree with the observed data by the ALICE collaboration. The agreement confirms the S = −2 baryon-baryon potentials from lattice QCD.

    Scopus

    researchmap

  • Towards modeling cluster structure of 8Be with chiral interaction

    Tokuro Fukui

    Journal of Physics G: Nuclear and Particle Physics   49 ( 5 )   2022.5   ISSN:0954-3899 eISSN:1361-6471

     More details

    Language:Others   Publishing type:Research paper (scientific journal)   Publisher:{IOP} Publishing  

    How the nuclear force behaves in cluster states, in particular those consisting of the α clusters, has been investigated so far, but not yet elucidated. Today the chiral effective field theory (EFT) is established and it would shed new light on the microscopic understanding of the cluster states. We aim to address a possible source of the attraction in the cluster states of 8Be in view of the pion exchange. Namely, we investigate whether the two-pion-exchange interaction acts as a dominant attraction in the α + α system as predicted by a previous work. We describe theoretically the cluster structure of 8Be by the Brink model, for which the effective interaction is designed from the realistic nuclear force derived through the chiral EFT. The two-body matrix elements of the chiral interaction with the local-Gaussian bases are formulated within the approximation of the spin-isospin saturation forming an α particle. Introducing a global prefactor to the chiral interaction phenomenologically, the ground and low-lying excited states of 8Be, the scattering phase shift of the α-α system as well, are satisfactorily depicted. The attraction in the cluster states is found to be stemming from the two-pion-exchange contributions dominantly, along with nonnegligible short-range terms. The present work can be the foundation towards constructing realistic cluster models, by which the cluster states will be revealed microscopically in the next step.

    DOI: 10.1088/1361-6471/ac58b3

    Scopus

    researchmap

  • Femtoscopic study of coupled-channel baryon-baryon interactions with S = −2

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, T. Hatsuda

    Proceedings of Science   380   2022.5

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    The correlation functions of pΞ− and ΛΛ pairs from pp and pA collisions are studied in the coupled-channel framework using the NΞ-ΛΛ coupled-channel baryon-baryon potentials obtained in the lattice QCD calculation at almost physical quark masses. The pΞ− correlation function is calculated to be significantly enhanced from the pure Coulomb case, while the ΛΛ correlation function is slightly enhanced from that of the pure fermion quantum statistics. These features reflect the large and small scattering lengths in the pΞ− and ΛΛ channels in magnitude, and agree with the observed data by the ALICE collaboration. The agreement confirms the S = −2 baryon-baryon potentials from lattice QCD.

  • Femtoscopic study of coupled-channels N Ξ and Λ Λ interactions

    Y. Kamiya, K. Sasaki, T. Fukui, T. Hyodo, K. Morita, K. Ogata, A. Ohnishi, T. Hatsuda

    Physical Review C   105 ( 1 )   2022.1   ISSN:2469-9985 eISSN:2469-9993

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The momentum correlation functions of S=-2 baryon pairs (pΞ- and ΛΛ) produced in high-energy pp and pA collisions are investigated on the basis of the coupled-channels formalism. The strong interaction is described by the coupled-channels HAL QCD potential obtained by lattice QCD simulations near physical quark masses, while the hadronic source function is taken to be a static Gaussian form. The coupled-channels effect, the threshold difference, the realistic strong interaction, and the Coulomb interaction are fully taken into account for the first time in the femtoscopic analysis of baryon-baryon correlations. The characteristic features of the experimental data for the pΞ- and ΛΛ pairs at the Large Hadron Collider are reproduced quantitatively with a suitable choice of nonfemtoscopic parameters and the source size. The agreement between theory and experiment indicates that the NΞ (ΛΛ) interaction is moderately (weakly) attractive without having a quasibound (bound) state.

    DOI: 10.1103/PhysRevC.105.014915

    Scopus

    researchmap

  • Shell-model study of titanium isotopic chain with chiral two- And three-body forces

    L. Coraggio, G. De Gregorio, A. Gargano, N. Itaco, T. Fukui, Y. Z. Ma, F. R. Xu

    Physical Review C   104 ( 5 )   2021.11

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The even-even Ti isotopic chain, from A=42 to 70, has been studied within the nuclear shell-model framework by employing an effective Hamiltonian which is derived by way of many-body perturbation theory from a chiral potential with two- and three-body forces, and includes three-body contributions which account for Pauli principle violations in nuclei with more than two valence particles. We consider Ca40 as a closed core and a model space spanned by the neutron and proton 0f1p orbitals with the addition of the 0g9/2 orbital for neutrons. Calculated two-neutron separation energies and excitation energies of the yrast 2+ states are reported and compared with the experimental data, which are available up to Ti62. The present study intends to investigate the effects of the adopted effective interactions on the evolution of the shell structure.

    DOI: 10.1103/PhysRevC.104.054304

  • Realistic Shell Model with Chiral Interaction and Its Application to Drip-Line Predictions

    Tokuro Fukui, Luigi Coraggio, Giovanni De Gregorio, Angela Gargano, Nunzio Itaco, Yuanzhuo Ma, Furong Xu

    Few-Body Systems   62 ( 3 )   2021.9

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We employ the shell model with the chiral two- and three-nucleon forces. The effective Hamiltonian relevant to the valence-model space is computed microscopically. This framework is applied to the study of the neutron-drip line of the calcium isotopes. Our simulation shows that the calculated two-neutron separation energies are consistent with those of currently available experiment and 70Ca is possibly bound, as other theoretical attempts predict.

    DOI: 10.1007/s00601-021-01655-8

  • Femtoscopic Study of NΞ Interaction and Search for the H Dibaryon State Around the NΞ Threshold

    Akira Ohnishi, Y. Kamiya, K. Sasaki, T. Fukui, T. Hatsuda, T. Hyodo, K. Morita, K. Ogata

    Few-Body Systems   62 ( 3 )   2021.9

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We study the momentum correlation functions of pΞ - and Λ Λ pairs produced in high-energy nuclear collisions by using the coupled-channel framework and the NΞ - Λ Λ coupled-channel baryon-baryon potentials recently obtained from lattice QCD calculations at almost physical quark masses. The calculated results are found to well describe the correlation function data from pp and pPb collisions. This agreement confirms the S= - 2 baryon-baryon potentials from lattice QCD and supports the existence of the H dibaryon as a virtual state around the NΞ threshold.

    DOI: 10.1007/s00601-021-01626-z

  • Three-body description of C 9: Role of low-lying resonances in breakup reactions

    Jagjit Singh, Takuma Matsumoto, Tokuro Fukui, Kazuyuki Ogata

    Physical Review C   104 ( 3 )   2021.9

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Background: The C9 nucleus and related capture reaction, B8(p,γ)C9, have been intensively studied with an astrophysical interest. Due to the weakly bound nature of C9, its structure is likely to be described as the three-body (Be7+p+p). Its continuum structure is also important to describe reaction processes of C9, with which the reaction rate of the B8(p,γ)C9 process have been extracted indirectly. Purpose: We preform three-body calculations on C9 and discuss properties of its ground and low-lying states via breakup reactions. Methods: We employ the three-body model of C9 using the Gaussian-expansion method combined with the complex-scaling method. This model is implemented in the four-body version of the continuum-discretized coupled-channels method, by which breakup reactions of C9 are studied. The intrinsic spin of Be7 is disregarded. Results: By tuning a three-body interaction in the Hamiltonian of C9, we obtain the low-lying 2+ state with the resonant energy 0.781 MeV and the decay width 0.137 MeV, which is consistent with the available experimental information and a relatively high-lying second 2+ wider resonant state. Our calculation predicts also sole 0+ and three 1- resonant states. We discuss the role of these resonances in the elastic breakup cross section of C9 on Pb208 at 65 and 160 MeV/nucleon. Conclusions: The low-lying 2+ state is probed as a sharp peak of the breakup cross section, while the 1- states enhance the cross section around 3 MeV. Our calculations will further support the future and ongoing experimental campaigns for extracting astrophysical information and evaluating the two-proton removal cross sections.

    DOI: 10.1103/PhysRevC.104.034612

  • Effect of deuteron breakup on the deuteron- Ξ correlation function

    Kazuyuki Ogata, Tokuro Fukui, Yuki Kamiya, Akira Ohnishi

    Physical Review C   103 ( 6 )   2021.6

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Background: The hadron-deuteron correlation function has attracted much interest as a potential method to access three-hadron interactions. However, the weakly bound nature of deuterons has not been considered in the preceding studies. Purpose: The breakup effect of deuterons in the deuteron-Ξ- (d-Ξ-) correlation function CdΞ- is investigated. Methods: The d-Ξ- scattering is described by a nucleon-nucleon-Ξ three-body reaction model. The continuum-discretized coupled-channels method, which is a fully quantum-mechanical and nonperturbative reaction model, is adopted. Results: CdΞ- turns out to be sensitive to the strong interaction and enhanced by the deuteron breakup effect by 6%-8% for a d-Ξ- relative momentum below about 70 MeV/c. Low-lying neutron-neutron continuum states are responsible for this enhancement. Conclusions: Within the adopted model, the deuteron breakup effect on CdΞ- is found to be appreciable but not very significant. Except for the enhancement by several percent, studies on CdΞ- without the deuteron breakup effect can be justified.

    DOI: 10.1103/PhysRevC.103.065205

  • Universality in COVID-19 spread in view of the Gompertz function

    Akira Ohnishi, Yusuke Namekawa, Tokuro Fukui

    Progress of Theoretical and Experimental Physics   2020 ( 12 )   2020.12

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We demonstrate that universal scaling behavior is observed in the current coronavirus (SARS-CoV-2) spread, the COVID-19 pandemic, in various countries. We analyze the numbers of infected people who tested positive (cases) in 11 selected countries (Japan, USA, Russia, Brazil, China, Italy, Indonesia, Spain, South Korea, UK, and Sweden). By using a double exponential function called the Gompertz function, f G (x)=exp(-e-x), the number of cases is well described as N(t)=N 0 f G(γ(t-t0)), where N0, γ, and t 0 are the final number of cases, the damping rate of the infection probability, and the peak time of the daily number of new cases, dN(t)/dt, respectively. The scaled data of cases in most of the analyzed countries are found to collapse onto a common scaling function f G(x) with x=γ(t-t_0) being the scaling variable in the range of f G(x)± 0.05. The recently proposed indicator, the so-called K value, the increasing rate of cases in one week, is also found to show universal behavior. The mechanism for the Gompertz function to appear is discussed from the time dependence of the produced pion numbers in nucleus-nucleus collisions, which is also found to be described by the Gompertz function.

    DOI: 10.1093/ptep/ptaa148

  • Shell-model study of calcium isotopes toward their drip line

    L. Coraggio, G. De Gregorio, A. Gargano, N. Itaco, T. Fukui, Y. Z. Ma, F. R. Xu

    Physical Review C   102 ( 5 )   2020.11

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We report in this paper a study in terms of the nuclear shell model about the location of the calcium isotopes drip line. The starting point is considering the realistic two-body potential derived by Entem and Machleidt within chiral perturbation theory at next-to-next-to-next-to-leading order (N3LO), as well as a chiral three-body force at next-to-next-to-leading order (N2LO) whose structure and low-energy constants are consistent with the two-body potential. Then we construct the effective single-particle energies and residual interaction needed to diagonalize the shell-model Hamiltonian. The calculated two-neutron separation energies agree nicely with experiment until Ca56, which is the heaviest isotope whose mass has been measured, and do not show any sign of two-neutron emission until Ca70. We discuss the role of the choice of the model space in determining the neutron drip line, and also the dependence of the results on the parameters of the shell-model Hamiltonian.

    DOI: 10.1103/PhysRevC.102.054326

  • He 8 and Li 9 cluster structures in light nuclei

    Naoyuki Itagaki, Tokuro Fukui, Junki Tanaka, Yuma Kikuchi

    Physical Review C   102 ( 2 )   2020.8

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The possibility of the He8 and Li9 clusters in atomic nuclei is discussed. Until now most of the clusters in the conventional models have been limited to the closures of the three-dimensional harmonic oscillators, such as He4, O16, and Ca40. In the neutron-rich nuclei, however, the neutron-to-proton ratio (N/Z) is not unity, and it is worthwhile to think about more neutron-rich objects with N>Z as the building blocks of cluster structures. Here the nuclei with the neutron number six, which is the subclosure of the p3/2 subshell of the jj-coupling shell model, are assumed to be clusters, and thus we study the He8 and Li9 cluster structures in Be16 (He8+He8), B17 (He8+Li9), C18 (Li9+Li9), and C24 (He8+He8+He8). Recent progress of the antisymmetrized quasi-cluster model (AQCM) enables us to utilize jj-coupling shell-model wave functions as the clusters rather easily. It is shown that the He8+Li9 and Li9+Li9 cluster configurations cover the lowest shell-model states of B17 and C18, respectively. To predict cluster states with large relative distances, we increase the expectation value of the principal quantum numbers by adding the nodes to the lowest states under the condition that the total angular momentum is unchanged (equal to Jπ=0+). As a result, developed cluster states are obtained around the corresponding threshold energies. The rotational band structure of C24, which reflects the symmetry of equilateral triangular configuration (D3h symmetry) of three He8 clusters, also appears around the threshold energy. We suggest a novel mechanism whereby the spin-orbit interaction induces the clustering, which is distinctive of neutron-rich nuclei.

    DOI: 10.1103/PhysRevC.102.024332

  • Chiral three-nucleon force and continuum for dripline nuclei and beyond

    Y. Z. Ma, F. R. Xu, L. Coraggio, B. S. Hu, J. G. Li, T. Fukui, L. De Angelis, N. Itaco, A. Gargano

    Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics   802   2020.3

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Three-nucleon force and continuum play important roles in reproducing the properties of atomic nuclei around driplines. Therefore it is valuable to build up a theoretical framework where both effects can be taken into account to solve the nuclear Schrödinger equation. To this end, in this letter, we have expressed the chiral three-nucleon force within the continuum Berggren representation, so that bound, resonant and continuum states can be treated on an equal footing in the complex-momentum space. To reduce the model dimension and computational cost, the three-nucleon force is truncated at the normal-ordered two-body level and limited in the sd-shell model space, with the residual three-body term being neglected. We choose neutron-rich oxygen isotopes as the test ground because they have been well studied experimentally, with the neutron dripline determined. The calculations have been carried out within the Gamow shell model. The quality of our results in reproducing the properties of oxygen isotopes around the neutron dripline shows the relevance of the interplay between three-nucleon force and the coupling to continuum states. We also analyze the role played by the chiral three-nucleon force, by dissecting the contributions of the 2π exchange, 1π exchange and contact terms.

    DOI: 10.1016/j.physletb.2020.135257

  • Chiral three-body force and monopole properties of shell-model Hamiltonian

    Tokuro Fukui, Luigi Coraggio, Luca De Angelis, Angela Gargano, Nunzio Itaco, Yuanzhuo Ma, Furong Xu

    EPJ Web of Conferences   223   01018 - 01018   2019.12

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    So far, the nature of three-nucleon forces (3NFs) derived by the chiral effective field theory has been intensively investigated by various theoretical approaches. In this work, to address the chiral 3NF within the shell-model framework, three-body matrix elements are formulated in terms of the harmonic oscillator basis functions, by adopting the nonlocal regulator. We perform a benchmark test for p-shell nuclei inorder to confirm our framework. Then we show that the contribution of the 3NF to the monopole component of the effective shell model Hamiltonian plays an essential role to account for the shell evolution of f p-shell nuclei.

    DOI: 10.1051/epjconf/201922301018

  • Contribution of chiral three-body forces to the monopole component of the effective shell-model Hamiltonian

    Y. Z. Ma, L. Coraggio, L. De Angelis, T. Fukui, A. Gargano, N. Itaco, F. R. Xu

    Physical Review C   100 ( 3 )   2019.9

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We present a study of the role played by realistic three-body forces in providing a reliable monopole component of the effective shell-model Hamiltonian. To this end, starting from a nuclear potential built up within the chiral perturbation theory, we derive effective shell-model Hamiltonians with and without the contribution of the three-body potential and compare the results of shell-model calculations with a set of observables that evidence shell-evolution properties. The testing ground of our investigation is nuclei belonging to the fp shell, since the shell-evolution towards shell closures in Ca48 and Ni56 provides a paradigm for shell-model Hamiltonians. Our analysis shows that only by including contributions of the three-body force is the monopole component of the effective shell-model Hamiltonian then able to reproduce the experimental shell evolution towards and beyond the closure at N=28.

    DOI: 10.1103/PhysRevC.100.034324

  • Erratum to “Investigation of spatial manifestation of α clusters in 16O via α-transfer reactions” (Nuclear Physics, Section A (2019) 983 (38–52), (S037594741830513X), (10.1016/j.nuclphysa.2018.12.024))

    Tokuro Fukui, Yoshiko Kanada-En'yo, Kazuyuki Ogata, Tadahiro Suhara, Yasutaka Taniguchi

    Nuclear Physics A   988   59 - 60   2019.8

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We have found that, in the original paper, the calculated values listed in Table 4 and 5 [Table presented] should have been divided by a factor 9. This is due to the absence of the prefactor

    DOI: 10.1016/j.nuclphysa.2019.02.005

  • Renormalization of the Gamow-Teller operator within the realistic shell model

    L. Coraggio, L. De Angelis, T. Fukui, A. Gargano, N. Itaco, F. Nowacki

    Physical Review C   100 ( 1 )   2019.7

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    In nuclear structure calculations, the choice of a limited model space, due to computational needs, leads to the necessity to renormalize the Hamiltonian as well as any transition operator. Here, we present a study of the renormalization procedure and effects of the Gamow-Teller operator within the framework of the realistic shell model. Our effective shell-model operators are obtained, starting from a realistic nucleon-nucleon potential, by way of the many-body perturbation theory in order to take into account the degrees of freedom that are not explicitly included in the chosen model space. The theoretical effective shell-model Hamiltonian and transition operators are then employed in shell-model calculations, whose results are compared with data of Gamow-Teller transition strengths and double-β half-lives for nuclei which are currently of interest for the detection of the neutrinoless double-β decay process, in a mass interval ranging from A=48 up to A=136. We show that effective operators are able to reproduce quantitatively the spectroscopic and decay properties without resorting to an empirical quenching neither of the axial coupling constant gA, nor of the spin and orbital gyromagnetic factors. This should assess the reliability of applying present theoretical tools to this problematic.

    DOI: 10.1103/PhysRevC.100.014316

  • Realistic shell model description of beta decay

    Angela Gargano, Luigi Coraggio, Luca De Angelis, Tokuro Fukui, Nunzio Itaco

    EPJ Web of Conferences   194   2018.11

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    In this paper, we extend our previous realistic shell-model study of Gamow-Teller strengths and double-β decay properties for nuclei around 132Sn to lighter mass nuclei. The effective shell-model Hamiltonian and transition operators are microscopically derived by way of many-body perturbation theory, without resorting to empirical parameters. Our main aim is to further check the reliability of our approach and verify its stability in other mass regions. Calculated energy spectra as well as electric-quadrupole and β-decay properties are presented for 76Ge and 82Se and compared with the experimental data, together with some results for 130Te and 136Xe already reported in our previous paper. Finally, some preliminary results of nuclear matrix elements responsible for the neutrinoless double beta decay, calculated by using the bare operator, are shown.

    DOI: 10.1051/epjconf/201819402007

  • Neutron-hole states in 131Sn and spin-orbit splitting in neutron-rich nuclei

    R. Orlandi, S. D. Pain, S. Ahn, A. Jungclaus, K. T. Schmitt, D. W. Bardayan, W. N. Catford, R. Chapman, K. A. Chipps, J. A. Cizewski, C. G. Gross, M. E. Howard, K. L. Jones, R. L. Kozub, B. Manning, M. Matos, K. Nishio, P. D. O’ Malley, W. A. Peters, S. T. Pittman, A. Ratkiewicz, C. Shand, J. F. Smith, M. S. Smith, T. Fukui, J. A. Tostevin, Y. Utsuno

    Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics   785   615 - 620   2018.10

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    In atomic nuclei, the spin-orbit interaction originates from the coupling of the orbital motion of a nucleon with its intrinsic spin. Recent experimental and theoretical works have suggested a weakening of the spin-orbit interaction in neutron-rich nuclei far from stability. To study this phenomenon, we have investigated the spin-orbit energy splittings of single-hole and single-particle valence neutron orbits of 132Sn. The spectroscopic strength of single-hole states in 131Sn was determined from the measured differential cross sections of the tritons from the neutron-removing 132Sn(d, t)131Sn reaction, which was studied in inverse kinematics at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The spectroscopic factors of the lowest 3/2+, 1/2+ and 5/2+ states were found to be consistent with their maximal values of (2j+1), confirming the robust N=82 shell closure at 132Sn. We compared the spin-orbit splitting of neutron single-hole states in 131Sn to those of single-particle states in 133Sn determined in a recent measurement of the 132Sn(d, p)133Sn reaction. We found a significant reduction of the energy splitting of the weakly bound 3p orbits compared to the well-bound 2d orbits, and that all the observed energy splittings can be reproduced remarkably well by calculations using a one-body spin-orbit interaction and a Woods–Saxon potential of standard radius and diffuseness. The observed reduction of spin-orbit splitting can be explained by the extended radial wavefunctions of the weakly bound orbits, without invoking a weakening of the spin-orbit strength.

    DOI: 10.1016/j.physletb.2018.08.005

  • Two-neutrino Double-Beta Decay within the Realistic Shell Model

    L. Coraggio, L. De Angelis, T. Fukui, A. Gargano, N. Itaco

    Journal of Physics: Conference Series   1056 ( 1 )   2018.7

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    We report on the calculation of double-β decay properties of 130Te and 136Xe within the framework of the realistic shell model. The effective shell-model Hamiltonian and Gamow-Teller transition operator are derived by way of many-body perturbation theory, in order to not to resort to an empirical quenching of the axial coupling constant g A. The results compare well with experimental data, paving the way to the calculation of the neutrinoless double-β decay nuclear matrix element for the nuclei that are currently the experimental target for the detection of this process. In this work we investigate about the perturbative properties of our approach, and the theoretical reliability of the realistic shell model.

    DOI: 10.1088/1742-6596/1056/1/012012

  • Erratum: Theoretical investigation of two-particle two-hole effects on spin-isospin excitations through charge-exchange reactions (Physical Review C (2017) 96 (054608) DOI: 10.1103/PhysRevC.96.054608)

    T. Fukui, F. Minato

    Physical Review C   97 ( 2 )   2018.2

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We have found two typographical errors in the original paper. First, the prefactor on the right-hand-side of Eq. (25) was wrong. It should be replaced by (Formula Presented). Note that all the numerical calculations were carried out using the correct prefactor and parameter. The results and conclusions of the original article remain unchanged.

    DOI: 10.1103/PhysRevC.97.029901

  • Theoretical investigation of two-particle two-hole effects on spin-isospin excitations through charge-exchange reactions

    Tokuro Fukui, Futoshi Minato

    Physical Review C   96 ( 5 )   2017.11

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Background: Coherent one-particle one-hole (1p1h) excitations have given us effective insights into general nuclear excitations. However, the two-particle two-hole (2p2h) excitation beyond 1p1h is now recognized as critical for the proper description of experimental data of various nuclear responses. Purpose: The spin-flip charge-exchange reactions Ca48(p,n)Sc48 are investigated to clarify the role of the 2p2h effect on their cross sections. The Fermi transition of Ca48 via the (p,n) reaction is also investigated in order to demonstrate our framework. Methods: The transition density is calculated microscopically with the second Tamm-Dancoff approximation, and the distorted-wave Born approximation is employed to describe the reaction process. A phenomenological one-range Gaussian interaction is used to prepare the form factor. Results: For the Fermi transition, our approach describes the experimental behavior of the cross section better than the Lane model, which is the conventional method. For spin-flip excitations including the GT transition, the 2p2h effect decreases the magnitude of the cross section and does not change the shape of the angular distribution. The Δl=2 transition of the present reaction is found to play a negligible role. Conclusions: The 2p2h effect will not change the angular-distributed cross section of spin-flip responses. This is because the transition density of the Gamow-Teller response, the leading contribution to the cross section, is not significantly varied by the 2p2h effect.

    DOI: 10.1103/PhysRevC.96.054608

  • Interference effect between neutron direct and resonance capture reactions for neutron-rich nuclei

    Futoshi Minato, Tokuro Fukui

    EPJ Web of Conferences   163   2017.11

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    Interference effect of neutron capture cross section between the compound and direct processes is investigated. The compound process is calculated by resonance parameters and the direct process by the potential model. The interference effect is tested for neutron-rich 82Ge and 134Sn nuclei relevant to r-process and light nucleus 13C which is neutron poison in the s-process and produces long-lived radioactive nucleus 14C (T1/2 = 5700 y). The interference effects in those nuclei are significant around resonances, and low energy region if s-wave neutron direct capture is possible. Maxwellian averaged cross sections at kT = 30 and 300 keV are also calculated, and the interference effect changes the Maxwellian averaged capture cross section largely depending on resonance position.

    DOI: 10.1051/epjconf/201716300037

  • Probing surface distributions of a clusters in20Ne via α-transfer reaction

    T. Fukui, Y. Taniguchi, T. Suhara, Y. Kanada-En'Yo, K. Ogata

    Journal of Physics: Conference Series   863 ( 1 )   2017.7

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    Although several analyses of the α-transfer reaction16O(6Li, d)20Ne using the distorted wave Born approximation have been performed with the aim to clarify the α-cluster structure of20Ne, they have resulted in poor information on the clustering due to insufficiency of models for the analyses. In this work we propose a precise model employing the coupled-channels Born approximation with the microscopically calculated cluster wave function to elucidate the surface manifestation of the α-particle in the ground state of20Ne. Our calculation has shown improvement of the theoretical calculation compared with that in the previous analyses. We have confirmed numerically that the angular distributed cross section at the forward angles probes only the surface region of the α-cluster wave function. The breakup effect of6Li has been investigated and concluded that only the back coupling is important for the (6Li, d) reaction.

    DOI: 10.1088/1742-6596/863/1/012036

  • Recent developments in the eikonal description of the breakup of exotic nuclei

    P. Capel, F. Colomer, H. Esbensen, T. Fukui, R. C. Johnson, F. M. Nunes, K. Ogata

    Journal of Physics: Conference Series   724 ( 1 )   2016.7

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    The study of exotic nuclear structures, such as halo nuclei, is usually performed through nuclear reactions. An accurate reaction model coupled to a realistic description of the projectile is needed to correctly interpret experimental data. In this contribution, I briefly summarise the assumptions made within the modelling of reactions involving halo nuclei. I describe briefly the Continuum-Discretised Coupled Channel method (CDCC) and the Dynamical Eikonal Approximation (DEA) in particular and present a comparison between them for the breakup of 15C on Pb at 68AMeV. I show the problem faced by the eikonal approximation at low energy and detail a correction that enables its extension down to lower beam energies. A new reaction observable is also presented. It consists of the ratio between angular distributions for two different processes, such as elastic scattering and breakup. This ratio is completely independent of the reaction mechanism and hence is more sensitive to the projectile structure than usual reaction observables, which makes it a very powerful tool to study exotic structures far from stability.

    DOI: 10.1088/1742-6596/724/1/012005

  • Microscopic effective reaction theory for direct nuclear reactions

    Kazuyuki Ogata, Kosho Minomo, Masakazu Toyokawa, Michio Kohno, Takuma Matsumoto, Masanobu Yahiro, Yuma Kikuchi, Tokuro Fukui, Kazuki Yoshida, Kazuhito Mizuyama

    EPJ Web of Conferences   122   2016.6

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    Some recent activities with the microscopic effective reaction theory (MERT) on elastic, inelastic, breakup, transfer, and knockout processes are reviewed briefly. As a possible alternative to MERT, a description of elastic and inelastic scattering with the continuum particle-vibration coupling (cPVC) method is also discussed.

    DOI: 10.1051/epjconf/201612206003

  • Probing surface distributions of α clusters in Ne 20 via α-transfer reaction

    Tokuro Fukui, Yasutaka Taniguchi, Tadahiro Suhara, Yoshiko Kanada-En'Yo, Kazuyuki Ogata

    Physical Review C   93 ( 3 )   2016.3

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Background: Direct evidence of the α-cluster manifestation in bound states has not been obtained yet, although a number of experimental studies were carried out to extract the information of the clustering. In particular in conventional analyses of α-transfer reactions, there exist a few significant problems on reaction models, which are insufficient to qualitatively discuss the cluster structure. Purpose: We aim to verify the manifestation of the α-cluster structure from observables. As the first application, we plan to extract the spatial information of the cluster structure of the Ne20 nucleus in its ground state through the cross section of the α-transfer reaction O16(Li6,d)Ne20. Methods: For the analysis of the transfer reaction, we work with the coupled-channel Born approximation (CCBA) approach, in which the breakup effect of Li6 is explicitly taken into account by means of the continuum-discretized coupled-channel method based on the three-body α+d+O16 model. The two methods are adopted to calculate the overlap function between Ne20 and α+O16; one is the microscopic cluster model (MCM) with the generator coordinate method, and the other is the phenomenological two-body potential model (PM). Results: We show that the CCBA calculation with the MCM wave function gives a significant improvement of the theoretical result on the angular distribution of the transfer cross section, which is consistent with the experimental data. Employing the PM, it is discussed which region of the cluster wave function is probed on the transfer cross section. Conclusions: It is found that the surface region of the cluster wave function is sensitive to the cross section. The present work is situated as the first step in obtaining important information to systematically investigate the cluster structure.

    DOI: 10.1103/PhysRevC.93.034606

  • Breakup and Finite-Range Effects on the 8B(d,n)9C Reaction

    Tokuro Fukui, Kazuyuki Ogata, Masanobu Yahiro

    Proceedings of the Conference on Advances in Radioactive Isotope Science (ARIS2014)   2015.6

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    DOI: 10.7566/jpscp.6.030060

  • Extracting the Electric Dipole Breakup Cross Section of One-Neutron Halo Nuclei from Inclusive Breakup Observables

    Kazuki Yoshida, Tokuro Fukui, Kosho Minomo, Kazuyuki Ogata

    Proceedings of the Conference on Advances in Radioactive Isotope Science (ARIS2014)   2015.6

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    DOI: 10.7566/jpscp.6.030092

  • Extending the Eikonal Approximation to Low Energy

    Pierre Capel, Tokuro Fukui, Kazuyuki Ogata

    Proceedings of the Conference on Advances in Radioactive Isotope Science (ARIS2014)   2015.6

     More details

    Language:Others   Publishing type:Research paper (other academic)  

    DOI: 10.7566/jpscp.6.020037

  • Breakup and finite-range effects on the B 8 (d,n)9C reaction

    Tokuro Fukui, Kazuyuki Ogata, Masanobu Yahiro

    Physical Review C - Nuclear Physics   91 ( 1 )   2015.1

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The astrophysical factor of B8(p,γ)9C at zero energy, S18(0), is determined by a three-body coupled-channels analysis of the transfer reaction B8(d,n)9C at 14.4 MeV/nucleon. Effects of the breakup channels of d and C9 are investigated with the continuum-discretized coupled-channels method. It is found that, in the initial and final channels, respectively, the transfer process through the breakup states of d and C9, its interference with that through their ground states in particular, gives a large increase in the transfer cross section. The finite-range effects with respect to the proton-neutron relative coordinate are found to be about 20%. As a result of the present analysis, S18(0)=22±6eVb is obtained, which is smaller than the result of the previous distorted-wave Born approximation analysis by about 51%.

    DOI: 10.1103/PhysRevC.91.014604

  • Probing α-cluster distribution via α-transfer reaction

    Tokuro Fukui, Yasutaka Taniguchi, Tadahiro Suhara, Yoshiko Kanada-En'yo, Kazuyuki Ogata

    Journal of Physics: Conference Series   569   012023 - 012023   2014.12

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1742-6596/569/1/012023

  • Analysis of a low-energy correction to the eikonal approximation

    Tokuro Fukui, Kazuyuki Ogata, Pierre Capel

    Physical Review C - Nuclear Physics   90 ( 3 )   2014.9

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Extensions of the eikonal approximation to low energy (20 MeV/nucleon typically) are studied. The relation between the dynamical eikonal approximation (DEA) and the continuum-discretized coupled-channels method with the eikonal approximation (E-CDCC) is discussed. When Coulomb interaction is artificially turned off, DEA and E-CDCC are shown to give the same breakup cross section, within 3% error, of C15 on Pb208 at 20 MeV/nucleon. When the Coulomb interaction is included, the difference is appreciable and none of these models agrees with full CDCC calculations. An empirical correction significantly reduces this difference. In addition, E-CDCC has a convergence problem. By including a quantum-mechanical correction to E-CDCC for lower partial waves between C15 and Pb208, this problem is resolved and the result perfectly reproduces full CDCC calculations at a lower computational cost.

    DOI: 10.1103/PhysRevC.90.034617

  • Extracting the electric dipole breakup cross section of one-neutron halo nuclei from inclusive breakup observables

    Kazuki Yoshida, Tokuro Fukui, Kosho Minomo, Kazuyuki Ogata

    Progress of Theoretical and Experimental Physics   2014 ( 5 )   2014.5

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    We discuss how to extract an electric dipole (E1) breakup cross section σ(E1) from one-neutron removal cross sections measured at 250 MeV/nucleon by using 12C and 208Pb targets, σC-1n and σPb-1n, respectively. It is shown that, within about 5% error, σ(E1) can be obtained by subtracting ΓσC-1n from σPb-1n, as assumed in preceding studies. However, for the reaction of weakly bound projectiles, the scaling factor Γ is found to be about twice as large as that usually adopted. As a result, we obtain a 13-20% smaller σ(E1) of 31Ne at 250 MeV/nucleon than extracted in a previous analysis of experimental data. By compiling the values of Γ obtained for several projectiles, Γ = (2.30 ± 0.41) exp(-Sn) + (2.43 ± 0.21) is obtained, where Sn is the neutron separation energy. The target mass-number dependence of the nuclear parts of the one-neutron removal cross section and the elastic breakup cross section is also investigated. © The Author(s) 2014.

    DOI: 10.1093/ptep/ptu063

  • Investigation of the unbound21C nucleus via transfer reaction

    Tokuro Fukui, Kazuyuki Ogata

    EPJ Web of Conferences   66   03031 - 03031   2014.3

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    DOI: 10.1051/epjconf/20146603031

  • Determination of 8B(p, γ)9C Reaction Rate From 9C Breakup

    Tokuro Fukui, Kazuyuki Ogata, Kosho Minomo, Masanobu Yahiro

    Few-Body Systems   54 ( 7-10 )   1583 - 1586   2013.8

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The astrophysical factor of the 8B(p, γ)9C reaction at zero energy, S18(0), is determined from three-body model analysis of 9C breakup processes. The elastic breakup 208Pb(9C,p8B)208Pb at 65 MeV/nucleon and the one-proton removal reaction of 9C at 285 MeV/nucleon on C and Al targets are calculated with the continuum-discretized coupled-channels method (CDCC) and the eikonal reaction theory (ERT), respectively. As a result of the present analysis, S18(0) extracted from the two reactions shows good consistency, in contrast to in the previous studies. © 2013 Springer-Verlag Wien.

    DOI: 10.1007/s00601-012-0580-2

  • Study of Tensor Correlations in 4He via the 4He(p, dp)d and 4He(p, dp)pn Reactions

    K. Miki, A. Tamii, N. Aoi, T. Fukui, T. Hashimoto, K. Hatanaka, T. Ito, T. Kawabata, H. Matsubara, K. Ogata, H. J. Ong, H. Sakaguchi, S. Sakaguchi, T. Suzuki, J. Tanaka, I. Tanihata, T. Uesaka, T. Yamamoto

    Few-Body Systems   54 ( 7-10 )   1353 - 1356   2013.8

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Tensor correlations in 4He were studied via the (p, dp) reaction at the incident energy of 392 MeV with a focus on spin configurations of correlated pn pairs in 4He at high relative momenta (Prelcor). The preliminary results show that the correlated pn pair at Prelcor = 310 MeV/c predominantly has the channel spin S = 1, which is consistent with the characteristics of tensor correlations. © 2013 Springer-Verlag Wien.

    DOI: 10.1007/s00601-013-0611-7

  • Determination of the 8B(p,γ)9C reaction rate from 9C breakup

    Tokuro Fukui, Kazuyuki Ogata, Kosho Minomo, Masanobu Yahiro

    Physical Review C - Nuclear Physics   86 ( 2 )   2012.8

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    The astrophysical factor of 8B(p,γ)9C at zero energy, S 18(0), is determined from three-body model analysis of 9C breakup processes. The elastic breakup reaction 208Pb(9C,p8B)208Pb at 65 MeV/nucleon and the one-proton removal reaction of 9C at 285 MeV/nucleon on C and Al targets are calculated with the continuum-discretized coupled-channels method (CDCC) and the eikonal reaction theory (ERT), respectively. The asymptotic normalization coefficient (ANC) of 9C in the p-8B configuration, Cp8B9C, extracted from the two reactions shows good consistency, unlike in previous studies. As a result of the present analysis, S18(0)=66±10eVb is obtained. © 2012 American Physical Society.

    DOI: 10.1103/PhysRevC.86.022801

  • Three-body model analysis of subbarrier α transfer reaction

    Tokuro Fukui, Kazuyuki Ogata, Masanobu Yahiro

    Progress of Theoretical Physics   125 ( 6 )   1193 - 1204   2011.6

     More details

    Language:Others   Publishing type:Research paper (scientific journal)  

    Subbarrier α transfer reaction 13C(6Li, d) 17O(6.356 MeV, 1/2+) at 3.6 MeV is analyzed with an α + d +13C three-body model, and the asymptotic normalization coecient (ANC) for α+13C → 17O(6.356 MeV, 1/2+), which essentially determines the reaction rate of 13C(α, n)16O, is extracted. Breakup eects of 6Li in the initial channel and those of 17O in the nal channel are investigated with the continuum-discretized coupled-channels method (CDCC). The former is found to have a large back-coupling to the elastic channel, whereas the latter turns out to be signicantly small. The transfer cross section calculated with Born approximation to the transition operator, including breakup states of 6Li, gives (C17O *α13C)2 = 1.03 ± 0.29 fm-1. This result is consistent with the value obtained by the previous DWBA calculation.

    DOI: 10.1143/PTP.125.1193

▼display all

Books

  • 自然科学総合実験

    九州大学基幹教育院 編 (執筆担当 I-1–I-28)(Role:Joint author)

    学術図書出版社  2024.3 

     More details

    Language:Japanese   Book type:Scholarly book

    ISBN978-4-7806-1199-1, C3040

    Repository Public URL: https://hdl.handle.net/2324/7170868

Presentations

Professional Memberships

  • The Physical Society of Japan

    2010.7 - Present

      More details

  • The Physical Society of Japan

Committee Memberships

  • RIKEN   RIBF Theory Forum  

    2021.4 - Present   

      More details

Academic Activities

  • Screening of academic papers

    Role(s): Peer review

    2023

     More details

    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:2

  • Screening of academic papers

    Role(s): Peer review

    2022

     More details

    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

  • Screening of academic papers

    Role(s): Peer review

    2021

     More details

    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

  • Screening of academic papers

    Role(s): Peer review

    2020

     More details

    Type:Peer review 

    Number of peer-reviewed articles in foreign language journals:1

Research Projects

  • Exploration of Nuclear Clusters through Three-Nucleon Forces

    Grant number:23KK0250  2024 - 2026

    Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (Fostering Joint International Research)

    福井 徳朗

      More details

    Grant type:Scientific research funding

    国内外で注目されている原子核のクラスター現象は、物質の非一様性の創発という観点から重要である。原子核クラスターの形成メカニズムには未解明の点が多く残されている。特に、原子核を構成する核子間に働く相互作用がどのように寄与してクラスターを生み出すのかが解明されていない。基課題(21K13919)では核力の中でも2核子力の役割に焦点を当てた研究を進めており、これまでに重要な知見を得た。しかし、原子核クラスターの発現機構を解明するにはまだ難題が残されている。この国際共同研究では、この難題を克服するために、3核子力がクラスター化を促進するという予想を理論的に提唱し、基礎課題を発展させる。

    CiNii Research

  • JST ERATO 関口三体核力プロジェクト International coauthorship

    2023.10 - 2029.3

      More details

    詳細は以下に記述(https://www.jst.go.jp/erato/research_area/ongoing/jpmjer2304.html)。

  • Exploring Nuclear Giants: Structures and Reactions of Extremely Large Nuclei

    2023.7 - 2025.3

      More details

    Authorship:Principal investigator 

    量子系は典型的な大きさからどれくらい成長できるのだろうか?ある特定の原子核では、典型的な原子核の大きさよりも10倍ほどに膨れ上がった常識を覆すほど巨大な存在形態が理論的に示唆されている。しかし、そのような原子核を実験で確認する手法は確立していない。そこで我々は、非常に巨大な原子核を実証するための方法を理論的な側面から提案しようとしている。具体的には、低エネルギー移行反応が巨大原子核へのアクセスを可能にすることを示そうとしている。本研究は将来的な "nuclear giants" の研究のための礎となることが期待される。

  • Exploring Nuclear Giants: Structures and Reactions of Extremely Large Nuclei (https://usersoffice.rcnp.osaka-u.ac.jp/joint-usage/corenet)

    2023 - 2024

    大阪大学 RCNP COREnet

      More details

    Grant type:Contract research

  • 軽い核におけるクラスター構造の現実的核力に基づいた理論的研究

    2021.4 - 2026.3

      More details

    Authorship:Principal investigator 

    物質は階層性を持ち、階層間の普遍性や独自性の解明は物理学の最重要課題の一つである。近年、各階層におけるクラスター現象を通して、物質の階層構造を解明する研究が精力的に行われている。本研究では、物質階層の中でも、フェムトスケール(10のマイナス15乗メートル)の原子核のクラスター現象に注目する。原子核クラスターに関する課題は、クラスターと核力の関係が解明されていないことである。そこで、先端的な理論が導く核力に基づき、原子核クラスター構造を微視的に理解することを本研究の目的とする。これは、クラスター構造をpi中間子交換の回数と多体力の観点から理解する世界初の試みである。

  • Theoretical study of cluster structure of light nuclei based on realistic nuclear force

    Grant number:21K13919  2021 - 2025

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Early-Career Scientists

    福井 徳朗

      More details

    Authorship:Principal investigator  Grant type:Scientific research funding

    物質は階層性を持ち、階層間の普遍性や独自性の解明は物理学の最重要課題の一つである。近年、各階層におけるクラスター現象を通して、物質の階層構造を解明する研究が精力的に行われている。本研究では、物質階層の中でも、フェムトスケール(10のマイナス15乗メートル)の原子核のクラスター現象に注目する。原子核クラスターに関する課題は、クラスターと核力の関係が解明されていないことである。そこで、先端的な理論が導く核力に基づき、原子核クラスター構造を微視的に理解することを本研究の目的とする。これは、クラスター構造をpi中間子交換の回数と多体力の観点から理解する世界初の試みである。

    CiNii Research

  • 連続殻模型を用いた非束縛核の定量的理解 (https://www.jsps.go.jp/j-ab/ab_list/list_h30.html#subutsukeikagaku)

    2018 - 2019

    Japan Society for the Promotion of Science  Postdoctoral Fellowships for Research Abroad

      More details

    Grant type:Joint research

  • 多核子移行反応を用いた新奇な弱束縛状態の解明 (https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-16K17713/)

    Grant number:16K17713  2016

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists(A)or(B)

      More details

    Authorship:Principal investigator  Grant type:Scientific research funding

  • 質量数100以下の原子核による速い陽子捕獲過程の系統的記述 (https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-12J02396/)

    Grant number:12J02396  2012 - 2014

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for JSPS Fellows

      More details

    Authorship:Principal investigator  Grant type:Scientific research funding

  • 質量数100以下の原子核による速い陽子捕獲過程の系統的記述 (https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-12J02396/)

    2012 - 2014

    Japan Society for the Promotion of Science  Research Fellowships for Young Scientists

      More details

    Grant type:Joint research

▼display all

Educational Activities

  • 基幹教育のうち、「自然科学総合実験」や「基礎科学実習」、「基幹教育セミナー」を担当している。また総合科目「実践!はじめての研究」を担当し、学生の "研究" への挑戦を後押ししている。

Class subject

  • Basic Laboratory Experiments in Natural Science I

    2024.10 - 2024.12   Fall quarter

  • 実践!はじめての研究

    2023.12 - 2024.2   Winter quarter

  • 基礎科学実習

    2023.12 - 2024.2   Winter quarter

  • 自然科学総合実験

    2023.10 - 2023.12   Fall quarter

  • 基幹教育セミナー

    2023.6 - 2023.8   Summer quarter

  • 自然科学総合実験

    2023.4 - 2023.6   Spring quarter

  • Basic Laboratory Experiments in Natural Science Ⅱ

    2022.12 - 2023.2   Winter quarter

  • 基礎科学実習

    2022.12 - 2023.2   Winter quarter

  • 自然科学総合実験

    2022.10 - 2022.12   Fall quarter

  • 実践!はじめての研究

    2024.12 - 2025.2   Winter quarter

  • 基礎科学実習

    2024.12 - 2025.2   Winter quarter

  • Basic Laboratory Experiments in Natural Science Ⅱ

    2024.12 - 2025.2   Winter quarter

  • 自然科学総合実験

    2024.10 - 2024.12   Fall quarter

  • 自然科学総合実験

    2024.10 - 2024.12   Fall quarter

  • 実験で学ぶ自然科学

    2024.6 - 2024.8   Summer quarter

  • 実験で学ぶ自然科学

    2024.6 - 2024.8   Summer quarter

  • 基幹教育セミナー

    2024.6 - 2024.8   Summer quarter

  • 自然科学総合実験

    2024.4 - 2024.6   Spring quarter

  • 自然科学総合実験

    2024.4 - 2024.6   Spring quarter

▼display all

FD Participation

  • 2024.7   Role:Participation   Title:大学教職員職能開発FD 「⽣成AIを大学の教育・学習・業務にどのように組み込むか?-第四弾 教育現場における生成AIの導入事例-隣の教室の授業法-」

    Organizer:University-wide

  • 2024.7   Role:Participation   Title:物理学における反転授業の実践例

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2024.3   Role:Participation   Title:大学教職員職能開発FD「⽣成AIを大学の教育・学習・業務にどのように組み込むか?-第一弾 生成AIを使った授業デザイン支援のアイデア-」

    Organizer:University-wide

  • 2024.3   Role:Participation   Title:基幹教育ガイダンスFD

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2024.3   Role:Participation   Title:全学FD 「M2Bシステムの使い方」

    Organizer:University-wide

  • 2024.3   Role:Participation   Title:令和5年度春季基幹教育院FD

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2024.1   Role:Participation   Title:リベラルサイエンス教育開発FD 「ビッグヒストリーを活用した教養教育科目の試み」

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2023.5   Role:Participation   Title:基幹教育セミナーFD

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2023.3   Role:Participation   Title:令和4年度春季基幹教育院FD

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2023.3   Role:Participation   Title:基幹教育ガイダンスFD

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2023.3   Role:Participation   Title:【物理学科FD】物理数学の教育と効果的な演習に向けて

    Organizer:Undergraduate school department

  • 2022.12   Role:Participation   Title:リベラルサイエンス教育開発FD 「環境省『ぐぐるプロジェクト』とのコラボレーションでつくる学際的な授業」

    Organizer:[Undergraduate school/graduate school/graduate faculty]

  • 2022.12   Role:Participation   Title:リベラルサイエンス教育開発FD 「学際融合教育を考える ~科学コミュニケーション教育の事例を通して~」

    Organizer:[Undergraduate school/graduate school/graduate faculty]

▼display all

Social Activities

  • 理化学研究所2022年度和光地区一般公開

    理化学研究所  2022.4

     More details

    Audience:General, Scientific, Company, Civic organization, Governmental agency

    Type:Lecture

  • Dagli abissi alle stelle: KM3NeT Experience

    Giornata speciale a Città della Scienza, CITTÀ DELLA SCIENZA, Napoli, Italy  2017.9

     More details

    Audience:General, Scientific, Company, Civic organization, Governmental agency

    Type:Lecture

  • KM3NeT Experiment

    FUTURO REMOTO, Piazza del Plebiscito, Napoli, Italy  2017.5

     More details

    Audience:General, Scientific, Company, Civic organization, Governmental agency

    Type:Lecture

  • Listed in personal web page

     More details

Media Coverage

Activities contributing to policy formation, academic promotion, etc.

  • 2021.4 - Present  

    理化学研究所, RIBF理論研究推進会議 委員